Pen grip



FIG. 1 is the front bottom perspective view of the pen grip showing my new design;

FIG. 2 is a right side elevational view thereof which is a mirror image of the left side, front, and back views thereof;

FIG. 3 is a bottom plan view thereof; and,

FIG. 4 is a top plan view thereof.

The broken lines depicting environmental structure are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for the pen grip, as shown and described. 